Benign prostatic hypertrophy or hyperplasia (BPH) is one of the most common medical problems experienced by men over 50 years old. Urinary tract obstruction due to prostatic hyperplasia has been recognized since the earliest days of medicine. Hyperplastic enlargement of the prostate gland often leads to compression of the urethra, resulting in obstruction of the urinary tract and the subsequent development of symptoms including frequent urination, decrease in urinary flow, nocturia, pain, discomfort, and dribbling.
One surgical procedure for treating BPH is transurethral needle ablation (TUNA). The TUNA technique involves transurethral delivery of an electrically conductive needle to the prostate site. The needle penetrates the prostate in a direction generally perpendicular to the urethral wall, and delivers electrical current to ablate prostate tissue. The electrical current heats tissue surrounding the needle tip to destroy prostate cells, and thereby create a lesion within the prostate gland. The destroyed cells may be absorbed by the body, infiltrated with scar tissue or become non-functional.
Other transurethral ablation procedures involve delivery of microwave, radio frequency, acoustic, and light energy to the prostate gland. In addition, some procedures involve delivery of localized chemotherapy, drug infusions, collagen injections, or injections of agents which are then activated by light, heat or chemicals to destroy prostate tissue. These procedures, as well as the TUNA procedure, involve tissue trauma that can be painful for the patient. Accordingly, minimization of patient pain continues to be an objective in the design and delivery of transurethral prostate treatment procedures.
U.S. Pat. No. 6,551,300 to McGaffigan discloses a transurethral ablation device that delivers a topically applied anesthetic agent gel to a urethral wall. U.S. Published Patent Application no. 2002/0183740 to Edwards et al. discloses a transurethral ablation device to ablate prostate tissue via electrically conductive needles. Table 1 below lists documents that disclose devices for transurethral ablation of prostate tissue.
TABLE 1Patent NumberInventorsTitle2002/0183740Edwards et al.Medical probe device and methodU.S. Pat. No.McGaffiganDevice and method for delivery of6,551,300topically applied local anesthetic to wallforming a passage in tissue
All documents listed in Table 1 above are hereby incorporated by reference herein in their respective entireties. As those of ordinary skill in the art will appreciate readily upon reading the Summary of the Invention, Detailed Description of the Preferred Embodiments and claims set forth below, many of the devices and methods disclosed in the patents of Table 1 may be modified advantageously by using the techniques of the present invention.